The value of CT-guided discography in the diagnoses of discogenic low back pain

Objective:To evaluate the value of CT guided intervertebral discography in diagnosing discogenic low back pain.Method:80 patients diagnosed as chronic lumbar pain were cured by conservative methods more than 6 months and were not evidently alleviated.All patients underwent intervertebral discography by CT guide.The penetrated point and path were decided by the CT scan,when the needle reached the center of disc,injected the contrast agent(Ominipaque),and then the dose was recorded,patient's response to the pain was observed,and asked if the pain was consistent with the past.According to the Dallas Diseogram Descrip- tion(DDD)to classify the intervertebral disc.Statistical analysis of positive cases was performed on the age group,disc shape classification,contrast agent dose.Result:There were 53 patients with the positive interverte- bral discography(66.25%),involved 53 intervertebral discs,most of them were in the age of 41-50 years (92%).In the total 102 abnormal intervertebral discs,53 were positive.According to the DDD,the 3,4 grade accounted for 77.36% in the total positive eases.In the MRI,the positive discs were dark which suggested the degenerative change,and none of the normal disc was positive in the discography.In 38 cases which had the HIZ(high intensity zone)in the posterior rim of the intervertebral disc,there were 35 intervertebral discs with the positive discography,which occupied 66.04% in all positive intervertebral discs.In normal intervertebral disc,the contrast agent injected of 1.2±0.3ml.And in the abnormal intervertebral disc,the close induced the pain in the positive case averaged 3.2±1.4ml,and in the negative case averaged 3.4±1.8ml,both had no statistics difference.Conclusion:The intervertebral discography by CT guide is the important method to diag- nose the lumbar pain caused by the intervertebral disc,it can clearly show the rupture site and degree of the anulus fibrosus,and help locate the position precisely in the operation.